1. Field of the Invention
The present invention relates to an image pickup device with a function to pickup still pictures while imaging a moving picture, as well as its image pickup method.
2. Related Art
Among digital cameras in which picture signals of a subject picked up by a solid-state image pickup element such as a CCD are converted into digital signals and the resulting picture data are recorded on recording media, some have a moving picture pickup function in addition to the normal still picture pickup function, while some have a function to pickup pictures with voices that simultaneously records voices and still pictures or moving pictures.
In such digital cameras, a still picture pickup mode, in which still pictures are picked up, and a moving picture pickup mode, in which moving pictures are picked up, are independently provided as image pickup modes and the modes are switched one from the other through user operation such as a key operation.
Several methods have been proposed for picking up a still picture during picking up a moving picture using a digital camera. In one of such methods, when there is a user operation to pickup a still picture during a moving picture pickup operation, while moving picture frames are picked up at moving picture frame cycles in the moving picture pickup operation and stored in a buffer memory, a still picture is picked up and recorded while the next moving picture frame is recorded. In effect, in this method, the moving picture pickup processing and the still picture pickup processing take place in parallel.
In another method, when there is a user operation to pickup a still picture while picking up a moving picture, the operation to image and store moving picture frames is interrupted temporarily, a still picture is picked up and recorded during the interruption, and imaging and storing of moving picture frames are subsequently resumed. In other words, a still picture pickup operation is conducted through an interrupt processing. When the moving picture pickup operation is finished, frames for interpolation purposes that correspond to moving picture frames during the interrupted period, which is a period during which moving picture frames could not be picked up due to the still picture pickup processing, are separately created and stored; and when the moving picture is reproduced, interpolation frames are displayed in the interrupted period. In this way, a still picture pickup operation during a moving picture pickup operation is made possible.